Fastening element for fastening solar modules to an inclined roof surface

ABSTRACT

The invention relates to a fastening element for fastening solar modules to an inclined roof surface, including a base plate for fastening to a roof membrane of the roof surface or to a mounting rail supported on the roof membrane, at least one hook extending from the base plate for hanging a first frame of a first solar module, wherein the first frame in order to be hung is moved relative to the hook along a hanging direction, and a supporting wall extending opposite the hook from the base plate for supporting a second frame of a second solar module, wherein the supporting wall runs approximately perpendicularly to the hanging direction.

The invention relates to a fastening element for fastening solar modules to an inclined roof surface.

In accordance with the prior art it is generally known, in order to fasten solar modules to an inclined roof surface, to initially attach horizontally running mounting rails to the roof. The solar modules to be fastened are then rested on the horizontal mounting rails and are fastened by clamping by way of fastening elements latched to the horizontal rails or fastened by way of a clamped connection. In order to produce the clamping fastening it is necessary to first adjust the solar modules, to hold said modules in the adjusted position, and then to tighten clamping screws of the fastening elements. This process is laborious. For this, two installers are generally necessary, one of which adjusts and holds the solar module and the other produces the clamping fastening of the solar modules.

The object of the invention is to overcome the disadvantages according to the prior art. In particular, a fastening element is to be specified that enables a simple and rapid mounting of solar modules on an inclined roof surface.

This object is achieved by the features of claims 1 and 18. Expedient embodiment of the invention will emerge from the features of claims 2 to 17 and 19.

In accordance with the invention a fastening element for fastening solar modules to an inclined roof surface is proposed, comprising a base plate for fastening to a roof membrane of the roof surface or to a mounting rail supported on the roof membrane, at least one hook extending from the base plate for hanging a first frame of a first solar module, wherein the first frame in order to be hung is moved relative to the hook along a hanging direction, and a support wall extending opposite the hook from the base plate for supporting a second frame of a second solar module, wherein the support wall runs approximately perpendicularly to the hanging direction.

The proposed fastening element makes it possible to fasten solar modules to an inclined roof surface simply by hanging and supporting. With use of the proposed fastening element it is not necessary to produce a clamping connection, for example by fixing a clamping screw. It is possible with the proposed fastening element for solar modules to be attached quickly and easily to an inclined roof surface. The solar modules are held securely and reliably in the fastening element by the force of gravity.

In order to fasten the fastening element, at least two through-openings passing through the base plate are expediently provided. The fastening element may be fastened directly to the roof membrane, for example a trapezoidal sheet forming the roof membrane, or to a mounting rail supported on the roof membrane, for example a profiled tube produced for example from aluminium, by way of screws, drilling screws, rivets or the like passing through the through-openings. Alternatively, it is also possible to fasten the base plate to the roof membrane, for example by way of an adhesive, in particular a mounting adhesive.

The hook expediently has a slot running in the hanging direction for the insertion of a free leg of a first frame formed in the manner of a U-profile. In accordance with the prior art photovoltaic or solar modules are generally surrounded by a frame formed in the manner of a U-profile. Free legs of the U-profiles formed on a rear side of the solar module are directed inwardly and run for example parallel to a collector surface of the solar module. The free legs of the U-profile have, depending on design, a depth generally from 20 to 50 mm. The fastening element according to the invention uses the free legs usually provided anyway on the rear side of the solar modules for hanging in the hook, which for this purpose is advantageously formed as a slot.

In accordance with a further advantageous embodiment a first distance between an opening plane of the slot running parallel to the supporting wall and the opposite supporting wall is 50 to 120 mm, preferably 60 to 80 mm. This enables the use of the fastening element for a large number of solar modules available on the market. In order to mount a flat solar module the first frame is firstly inserted into the gap formed between the opening plane of the slot and the supporting wall. The first frame is then moved relative to the hook in the hanging direction, such that the free leg of the U-profile forming the first frame is introduced into the slot. A rear ventilation gap having a first width, which may be 30 to 100 mm, remains between an eaves-side first solar module hung in a fastening element and a ridge-side second solar module supported against the supporting wall of said fastening element.

The retaining element by way of example may be produced from an aluminium sheet cut by way of laser cutting and then bent. A cutting pattern of a laser cutting unit may be changed quickly and easily. Consequently, it is possible to supply retaining elements having a predefined first distance in accordance with the request of a builder. Here, the first distance may be set such that the solar modules are distributed uniformly with respect to a maximum available roof occupancy area. For this purpose the first width of the rear ventilation gap may be adjusted by varying the first distance, such that the solar modules uniformly fill out the maximum available roof occupancy area in the vertical direction.

In accordance with a particularly advantageous embodiment two of the hooks extend from the base plate distanced by a second width from 40 to 140 mm, preferably 70 to 120 mm, in such a way that two first frames of two first solar modules can be hung adjacently in said hooks. The supporting wall expediently has a height from 30 to 60 mm, preferably 35 to 50 mm. It is therefore adapted to the usual frame heights of conventional solar modules. A third width of the supporting wall is expediently 40 to 140 mm, preferably 70 to 120 mm. The supporting wall is therefore suitable for supporting two adjacently arranged second frames of the second solar modules. A fastening element having the above-mentioned features is thus suitable for fastening four solar modules simultaneously and proportionally in the regions of the corners thereof.

In accordance with a further particularly advantageous embodiment of the invention a bar overlapping the second frame in the mounted state extends at an angle from 80 to 100°, preferably 90°, from an upper edge of the supporting wall facing away from the base plate. The second frame is usually forced in the mounted state against the supporting wall by the force of gravity. The proposed overlapping bar additionally serves to counteract lifting forces caused by the wind.

The base plate, the at least one hook, and the supporting wall are advantageously produced integrally from a sheet metal or extruded profile. The sheet metal may be produced from aluminium or stainless steel. The profile may be produced from aluminium or plastic. The fastening element may be produced in particular also from an injection-moulded plastic.

In accordance with a further advantageous embodiment of the invention a supporting bar for supporting the first frame hung in two hooks extends between the hooks from the base plate. In particular when the fastening element is produced from a sheet metal and the two mutually opposed hooks are formed by bent portions, the proposed supporting bar provides additional stability against a deflection or a warping of the base plate, which for example may be caused by lifting wind forces. Irrespectively, the proposed supporting bar, with a suitable embodiment, provides an additional bearing surface for supporting the first frame. This further improves the retention of the solar module in the fastening element.

On an underside of the base plate facing away from the hook and the supporting wall, a spacer plate having a thickness in the range from 1 to 30 mm may be provided. The spacer plate may be produced from a plastic material or rubber material. It may have a profile on its further underside facing away from the base plate, which profile corresponds to a profile of the roof membrane. By way of example, the further underside may be formed in a manner corresponding to the form of a trapezoidal or corrugated sheet, a roof tile, or the like. If the spacer plate is produced from a elastic material, this adapts at least partially to the form of the roof membrane.

In accordance with a further provision of the invention a mounting element for mounting solar modules on an inclined roof surface is proposed, wherein a plurality of the fastening elements according to the invention are mounted on a mounting strip at a fixedly predefined distance A, in such a way that the hooks are oriented in the same direction. In order to fasten solar modules, a plurality of the proposed mounting elements are mounted on the roof membrane in a vertical orientation, in such a way that the fastening elements attached thereto are aligned horizontally with one another. A first solar module may then be hung via its first frame in the hooks in the region of the ridge-side corners in two adjacent fastening elements and may be supported on the supporting walls of further fastening elements in the region of the corners oriented towards the eaves side. A second solar module may additionally be mounted further up the roof slope in a similar manner, etc.

For the distance A the following relationship advantageously applies:

A=B _(Rahmen) −a−b−c+k,

wherein B_(Rahmen) is a width of the frame, a is a first depth of the hook, b is a second depth of the free leg of the first frame, c is a thickness of a profile base plate of the U-profile of the first frame, and k is a value in the range from 0 to 3 mm.

As a result of the proposed distance A it is ensured that the solar module is securely and reliably held by way of two fastening elements mounted successively on the mounting rail. When the first frame bears against the supporting surface of a first fastening element, the free leg of an opposite frame portion then bears against the end of the slot opposite the slot opening or at all events forms an expansion joint of at most 3 mm with the opposite end of the slot.

An exemplary embodiment of the invention will be explained in greater detail hereinafter on the basis of the figures, in which:

FIG. 1 shows a perspective that partial view of a mounting element with solar modules attached thereto,

FIG. 2 shows a perspective view of a first fastening element according to FIG. 1,

FIG. 3 shows a sectional view through a second fastening element,

FIG. 4 shows a perspective view of a second fastening element,

FIG. 5 shows a perspective view of the fastening element according to FIG. 4 with solar modules attached thereto,

FIG. 6 shows a perspective view of a third fastening element,

FIG. 7 shows a perspective view of a fourth fastening element,

FIG. 8 shows a perspective view of a fifth fastening element,

FIG. 9 shows a perspective view of a sixth fastening element,

FIG. 10 shows a perspective view of a seventh fastening element, and

FIG. 11 shows a perspective view of an eighth fastening element.

The mounting element shown in FIGS. 1 and 2 comprises a mounting strip 1 to be rested vertically on a roof membrane (not shown here), which mounting rail for example is formed from a profile, in particular a tube with a polygonal cross-section or the like, produced from aluminium. A ridge-side end of the mounting rail 1 is designated by F and an eaves-side end is designated by T. First fastening elements are attached to the mounting rail 1 at a predefined distance A and are designated generally by the reference sign 2.1. An eaves-side first solar module is designated by the reference sign S1, and a ridge-side second solar module is designated by the reference sign S2. Each of the solar modules S1, S2 has a frame produced for example from aluminium, of which the mutually opposed sides are each formed in the manner of a U-profile. A first frame of the first solar module S1 has a first free leg 3, which extends inwardly on an underside opposite a collector surface of the first solar module S1, i.e. extends in a direction located below the collector surface of the first solar module S1. Likewise, the second solar module S2 has a second frame having a second free leg 4.

As can be seen in particular from the figures, each fastening element has a base plate 5, which for example has a rectangular outline. Hooks 6 extend from two mutually opposed first edges of the base plate 5. Each of the hooks 6 has a slot 7 for the insertion of the free leg 3, 4. A hanging direction E of the free leg 3, 4 predefined by the hook 6 runs approximately parallel to the extension direction of the slot 7. Reference sign 8 designates a supporting wall, which extends from a second edge of the base plate 5, which extends perpendicularly to the first edges. In other words, the supporting wall 8 extends approximately perpendicularly to the hanging direction E predefined by the hooks 6. At an upper edge of the supporting wall 8 facing away from the base plate 5, a bar 9 extends and overlaps the second frame of the second solar module S2 in the mounted state.

In the case of the mounting element shown in FIG. 1 the hooks 6 are each oriented in the same direction, i.e. the fastening elements 2.1 are mounted such that the hanging direction E predefined by the hooks 6 points in the same direction.

FIG. 3 shows a partial sectional view through a further mounting element having a second fastening element 2.2 attached thereto. In the case of the second fastening element 2.2 a first supporting bar 9 a forming an edge of the slot 7 and extending from the base plate 5 is longer than in the case of the first fastening element 2.1. The fastening elements are formed similarly for the rest: an opening plane O of the hook 6 and the supporting wall 8 are distanced from one another at a first distance A1, such that a rear ventilation gap S is formed between the first solar module S1 and the second solar module S2 in the mounted state. The first distance for example is 50 to 120 mm, the first width B1 is advantageously 30 to 100 mm, in particular 40 to 60 mm. A second distance A2 between a rear wall R of the solar modules S1, S2 and a roof surface (not shown here) is advantageously 40 to 100 mm, particularly preferably 60 to 80 mm. A ratio between the first width B1 of the rear ventilation gap S and a frame width B_(Rahmen) (shown in FIG. 1) of the solar modules S1, S2 is expediently as follows:

B1/B _(Rahmen) =V,

wherein V may assume values in the range from 0.02 to 0.2, preferably 0.03 to 0.1.

For the distance shown in FIG. 1 the following relationship expediently applies:

A=B _(Rahmen) −a−b−c+k,

wherein

a is a first depth of the hook 6,

b is a second depth of the free leg 3 of the first frame,

c is a thickness of a profile base plate 10 of the U-profile of the first frame.

In the case of conventional frame profiles a double-chamber hollow profile may also be provided instead of the profile base plate 10. In this case the thickness c corresponds to the thickness of the double-chamber hollow profile.

The distance A may be selected such that, in the assembled state, the free leg 3 bears against an end of the slot 7. In this case:

A=B _(Rahmen) −a−b−c.

A gap or an expansion joint, which may assume values from 0 to 3 mm, may also be provided between the slot end and the free leg 3. In this case the distance A reduces accordingly by the value k.

A height H of the supporting wall 8 is adapted to a further height of the profile base plate 10 of the U-profile of the second frame. It is 30 to 60 mm, for example.

In the exemplary embodiment shown in FIGS. 4 and 5, a spacer plate 11 is attached to an underside of the base plate 5 facing towards the mounting rail 1 and may have a further thickness D in the range from 1 to 40 mm. The base plate 5 has through-openings 12 for fastening the second fastening element 2.2, for example on the mounting strip 1. The through-openings 12 also pass through the spacer plate 11, which for example may be fastened to the base plate 5 by way of an adhesive.

The fastening element shown in the figures is expediently produced integrally from an aluminium sheet. Here, the hooks 6 and also the supporting wall 8 are formed chamfers. Likewise, the bar 9 may be formed by a bent portion. In a gap formed between the mutually opposed hooks 6, a second supporting bar 13 extends from the base plate 5 in the case of the first 2.1 and the second fastening element 2.2, and may be formed likewise by a chamfer. As can be seen in particular from FIG. 5, the second supporting bar 13 is used to stiffen the base plate 5 and/or to support the free leg 3 inserted into the hook 6.

A second width B2 of the base plate 5 is expediently 60 to 120 mm. Accordingly, a distance between the mutually opposed hooks 6 is expediently 50 to 120 mm, preferably 80 to 110 mm.

A third width B3 of the supporting wall 8 advantageously lies in the range from 40 to 140 mm, preferably in the range from 70 to 120 mm. The supporting wall 8 may also be formed in a trapezoid-like manner.

In FIGS. 2 and 5 fastening elements are shown in which merely a first solar module S1 is hung in one of the two hooks 6. The fastening elements 2.1 and 2.2, however, are suitable for hanging two of the eaves-side first solar modules S1 in a single fastening element 2.1, 2.2. Likewise, a single fastening element 2.1, 2.2 is suitable for supporting two adjacently arranged ridge-side second solar modules S2 via the frames thereof against the supporting wall 8.

Although the fastening element shown in the figures is formed from a sheet metal part, it may also be that it is produced from injection-moulded plastic. It is also conceivable to produce the fastening element from an extruded profile. In this case, if the fastening element is to be suitable for the fastening of four solar modules, a milled recess or a notch must be provided in order to form two mutually opposed hooks 6.

In the case of the first and second fastening elements 2.1, 2.2 shown in FIGS. 1 to 5, four solar modules S1, S2 can be secured simultaneously in the region of their adjacent corners. The further fastening elements 2.3 to 2.8 shown in FIGS. 6 to 8 are formed more simply. They are suitable for the fastening merely of two solar modules S1, S2 arranged adjacently at the edge.

In the case of the third fastening element 2.3 shown in FIG. 6 and in the case of the fourth fastening element 2.4 shown in FIG. 7, the hook 6 is formed in each case by a leg 14 running parallel to the base plate 5. A slot height formed between the base plate 5 and the leg 14 remains substantially identical from the opening plane O to the end of the slot 7, i.e. changes at most by ±5%.

In the case of the fifth fastening element 2.5 shown in FIG. 8 the slot height by contrast tapers from the opening plane O in the direction of the end of the slot 7.

The third fastening element 2.3 shown in FIG. 6 is expediently produced by way of extrusion from steel or aluminium.

The fastening elements 2.4, 2.5 shown in FIGS. 7 and 8 by contrast may be produced by way of laser cutting and bending from an aluminium sheet or steel sheet. Here, the hook 6 may expediently be produced by a bent portion extending from the base plate 5. The hook 6 may have a further through-opening 15. The counterpiece corresponding thereto is not bent away from the base plate 5, but forms a fastening tongue 16 extending from the hook-side end of the base plate 5.

FIGS. 9 to 11 show a sixth, seventh and eighth fastening element 2.6, 2.7, 2.8, which are formed similarly to the third, fourth and fifth fastening element 2.3, 2.4, 2.5 (see FIGS. 6 to 8). Here, however, the base plate 5 is wider in each case. Here, a base plate width is advantageously 300 to 500 mm, in particular 380 to 420 mm. Furthermore, separate hooks 6 are provided at each of the free corners of the base plate 5, i.e. each of the fastening elements 2.6, 2.7, 2.8 shown in FIGS. 9 to 11 has two hooks 6 extending from the base plate 5. Reference is made to the description of FIGS. 6 to 8 with regard to the embodiment of the hooks 6, etc.

The sixth to eighth fastening elements 2.6 to 2.8 shown in FIGS. 9 to 11 are each suitable for hanging two adjacent solar modules S1, S2 in the two hooks 6 extending from the base plate 5. Furthermore, the fastening elements 2.6 to 2.8 are each suitable for supporting two adjacent further solar modules on the supporting wall 8. In other words, similarly to the first 2.1 and second fastening element 2.2, four solar modules S1, S2 can be fastened simultaneously using the sixth to eighth fastening elements 2.6 to 2.8 shown in FIGS. 9 to 11. It is nevertheless also possible to use the sixth to eighth fastening elements 2.6 to 2.8 merely to fasten two solar modules S1, S2 in that one solar module S1, S2 is hung in both hooks 6 and the other solar module S1, S2 is supported against the supporting wall 8.

The fastening elements 2.6, 2.7, 2.8 shown in FIGS. 9 to 11 are suitable in particular for fastening to trapezoidal sheets. The base plate width is designed here such that a maximum channel distance of commercially available trapezoidal sheets, which for example is 330 mm, is bridged. In other words the sixth, seventh and eighth fastening elements 2.6, 2.7 and 2.8 are formed in the manner of a “trapezoidal sheet bridge”, which can be fastened to two adjacent ridges of the trapezoidal sheet. For this purpose a plurality of through-openings 12 provided in a universal arrangement may be provided in the base plate 5. Here, the arrangement of the through-openings 12 is selected such that the fastening elements 2.6 to 2.8 can be fastened to adjacent chambers of commercially available trapezoidal sheets.

LIST OF REFERENCE SIGNS

-   1 mounting rail -   2.1 to 2.8 fastening element -   3 first free leg -   4 second free leg -   5 base plate -   6 hook -   7 slot -   8 supporting wall -   9 bar -   9 a first supporting bar -   10 profile base plate -   11 spacer plate -   12 through-opening -   13 second supporting bar -   14 leg -   15 further through-opening -   16 fastening tongue -   a first depth -   b second depth -   c thickness -   A distance -   A1 first distance -   A2 second distance -   B_(Rahmen) width of the frame -   B1 first width -   B2 second width -   B3 third width -   D further thickness -   E hanging direction -   F ridge-side end -   H height -   O opening plane -   R rear wall -   S rear ventilation gap -   S1 first solar module -   S2 second solar module -   T eaves-side end 

1-19. (canceled)
 20. A fastening element for fastening solar modules to an inclined roof surface, comprising: a base plate for fastening to a roof membrane of the roof surface or to a mounting rail supported on the roof membrane; at least one hook extending from the base plate for hanging a first frame of a first solar module, wherein the hook has a slot for the insertion of a free leg of the first frame formed in the manner of a U-profile and the extending direction of the slot runs approximately parallel to a hanging direction of the free leg; and a supporting wall extending opposite the hook from the base plate approximately perpendicularly to the hanging direction, wherein the supporting wall is configured to support a profile base plate of a second frame of a second solar module formed in the manner of a U-profile since the supporting wall has a height that is adapted to a further height of the profile base plate of the second frame, and a bar overlapping the second frame in the mounted state extends at an angle from 80 to 100° from an upper edge of the supporting wall facing away from the base plate.
 21. The fastening element according to claim 20, wherein at least two through-openings passing through the base plate are provided.
 22. The fastening element according to claim 20, wherein a first distance between an opening plane of the slot running parallel to the supporting wall and the opposite supporting wall is 50 to 120 mm, preferably 60 to 80 mm.
 23. The fastening element according to claim 20, wherein two of the hooks extend from the base plate in a manner distanced by a second width from 40 to 140 mm, preferably 70 to 120 mm, in such a way that two first frames of two first solar modules can be hung adjacently in said hooks.
 24. The fastening element according to claim 20, wherein a supporting bar for stiffening the base plate and/or for supporting the first frame hung in the two hooks extends between said hooks from the base plate.
 25. A fastening element according to claim 20, wherein the supporting wall has a height from 30 to 60 mm, preferably 35 to 50 mm.
 26. The fastening element according to claim 20, wherein a third width of the supporting wall is 40 to 140 mm, preferably 70 to 120 mm.
 27. The fastening element according to claim 20, wherein the base plate, the at least one hook, and the supporting wall are produced integrally from a sheet metal or from an extruded profile.
 28. The fastening element according to claim 20, wherein the sheet metal is produced from aluminium or stainless steel.
 29. The fastening element according to claim 20, wherein the profile is produced from aluminium or plastic.
 30. The fastening element according to claim 20, produced from injection-moulded plastic.
 31. The fastening element according to claim 20, wherein a spacer plate having a thickness in the range from 1 to 30 mm is provided on an underside of the base plate facing away from the hook and the supporting wall.
 32. The fastening element according to claim 20, wherein the spacer plate is produced from a plastic or rubber material.
 33. The fastening element according to claim 20, wherein the spacer plate and the base plate are produced from one piece.
 34. The fastening element according to claim 20, wherein the underside of the base plate or a further underside of the spacer plate are formed such that they can be placed in a substantially form-fitting manner against a conventional trapezoidal sheet or a conventional roof corrugated sheet.
 35. A mounting element for mounting solar modules on an inclined roof surface, wherein a plurality of the fastening elements according to claim 20 are mounted on a mounting rail at a fixedly predefined distance A, in such a way that the hooks are oriented in the same direction.
 36. The mounting element according to claim 35, wherein the following relationship applies for the distance A: A=B _(Rahmen) −a−b−c+k, wherein B_(Rahmen) is a width of the frame, a is a first depth of the hook, b is a second depth of the free leg of the first frame, c is a thickness of a profile baseplate of the U-profile of the first frame, and k is a value in the range from 0 to 3 mm. 